U.S. Pat. application Ser. No. 618,280 filed Sept. 30, 1975 now U.S. Pat. No. 4,054,092 issues Oct. 18, 1977 and assigned to the assignee of the present application, teaches a document counter in which documents are bottom-fed from a stack arranged in an infeed stacker and are stripped, separated, counted and/or endorsed and then restacked in an outfeed stacker in their original order.
The sheets are fed toward the cooperating stripper means and drive means by an eccentrically mounted jogger roller which serves to jog and hence loosen the stack, as well as imparting a "kick" to the bottom-most sheet thereby advancing this sheet toward the stripper means. The stripper means is preferably comprised of a pair of assemblies each having an upstream and downstream roller of respectively larger and smaller diameters and having one or more O-rings entrained therearound for imparting reverse drive to incoming sheets due to the frictional engagement between the O-rings and the incoming sheet (or sheets).
Feed means, comprised of either one or more feed belts or a plurality of O-rings, frictionally engages the bottom-most sheet to drive this sheet in the forward feed direction. The stripper and drive belts also cooperate to "corrugate" the sheets and enhances the stripping operation. In the case where a single sheet passes between the feed stripper means, the frictional engagement between the feed belt and the sheet exceeds the frictional engagement between the stripper O-rings and the sheet causing the sheet to be moved in the forward feed direction.
In the event that two sheets are simultaneously fed together, the frictional engagement between the sheets is less than the frictional engagement between the upper sheet and the stripper O-rings, causing the top-most sheet (or sheets) to be fed in the reverse direction while the bottom-most sheet is fed in the forward feed direction, whereupon acceleration means accelerates each sheet coming under the influence of the acceleration means to provide a gap between adjacent sheets to facilitate document counting.
Documents at the bottom-most portion of the stack have their downstream edges moved toward the stripper means preparatory to a stripping operation. In the event that the downstream ends of the documents are curled, folded or creased, which occurs quite often with very thin documents, engagement of the document with the stripper O-rings occurs in a region displaced upstream from the initial point of engagement between the stripper O-rings and the drive belt causing the document (or documents) to be driven backward, severely reducing the operating effectiveness of the device.
In order to alleviate this problem, guide fingers have been provided in the immediate vicinity of the stripper roller upstream surface for guiding the downstream edges of documents downwardly toward the feed belt means in order to frictionally engage the paper documents and thereby cause the documents to be moved in the forward feed direction.
By arranging the guide fingers so that they engage the documents at a position upstream of the stripper means, in order to facilitate the handling of curled or folded document edges, it was found that if the angle between the inclined guide finger and the feed belt is too large, the documents will not be fed properly between the drive and stripper means and if the angle of inclination between the guide finger and the feed belt is too small, the documents have been found to wedge between the guide fingers and the drive belts. The design problem therefore becomes quite critical in this regard.
In the outfeed stacker, light documents have a tendency to curl or become folded more easily than stiffer documents (i.e., of the order of tab cards) so that the cumulative effect of a stack of curled documents results in the upstream edges of the documents entering into the incoming path of the document subsequently fed to the stacker impeding the entry of the incoming document and thereby preventing the formation of a neat stack.